When evaluating denim, the most critical factor is Weight (measured in Ounces per square yard, oz/yd²). Lightweight denim (under 12 oz) is ideal for shirts and summer wear, while heavyweight denim (14 oz and above) is preferred for durable workwear and premium jeans. Additionally, check the Composition (e.g., 100% Cotton, Cotton-Polyester blends, or Cotton-Spandex for stretch). For high-end markets, prioritize Ring-Spun yarn over Open-End yarn for better texture and strength, and verify the Indigo Dyeing method (Rope Dyeing vs. Slasher Dyeing) to ensure color consistency and desired fading characteristics.